Sheet feeding mechanism



Dec. 28, 1954 e. s. ROWELL 2,698,175

SHEET FEEDING MECHANISM Original Filed Sept. 14, 1946 7 Sheets-Sheet 1INVENTOR. 650265 5. POWELL m EF SMAWA ATT6EN'EY6 Dec. 28, 1954 5, ROWELL2,698,17

SHEET FEEDING MECHANISM Original Filed Sept. 14, 1946 7 Sheets-Sheet 2INVENTOR. GEO/FM J. Wok/ LL AWOWEVKS.

Dec. 28, 1954 G. s. ROWELL 2,698,175

SHEET FEEDING MECHANISM Original Filed Sept. 14, 1946 7 Sheets-Sheet 3INVENTOR. 450M: 5. 2044 54 Dec. 1954 G. s. ROWELL 2,698,175

SHEET FEEDING MECHANISM Original Filed Sept. 14, 1946 7 Sheets-Sheet 4INVEN TOR. 22 Mme: .s. wwaL Dec. 28, 1954 G. S. ROWELL SHEET FEEDINGMECHANISM Original Filed Sept. 14, 1946 7 SheefcsSheet 5 INVENTOR.65026.6 5 POWELL 9770MB K5 Dec, 28, 1954 G. s. ROWELL, 2,698,W5

SHEET FEEDING MECHANISM Original Filed Sept. 14, 1946 7 Sheets-Sheet 6 iI l I i I I 42 I I06 I J22 WIL- 1 loz i" as: 5 E

E fig a amz/ INVENTOR. QED/F61 6. IPOWZLL BY m q [@WJM ATTOk/V'E V6United States Patent SHEET FEEDING MECHANISM George S. Rowell, Bedford,Ohio, assignor to The Chandler & Price Company, Cleveland, Ohio, acorporation of Ohio 14 Claims. (Cl. 271-11) This invention relates asindicated to sheet feeding mechanism for printing presses and the likeand particularly for cylinder printing presses.

There has been a steadily increasing need for a small cylinder printingpress of compact design having the adaptability required for use byjobbers. Such a press must be rapid in operation and versatile in thesizes and types of sheets which may be printed without elaborateadjustment of the sheet feeding mechanism. The sheet feeding mechanismof this invention may be employed in conjunction with various otherdevices such as folding machines but is especially adapted for use incylinder presses of the type above indicated.

It is, therefore, a primary object of this invention to provide sheetfeeding means capable of fast operation without necessity of anoverlapping feed, thereby permitting the feed table to be positionedmore closely to the impression cylinder with a resulting saving inspace.

Another object is to provide sheet registering means which will beeffective under conditions of high speed operation and very accurate.

A further object of this invention is to provide sheet feeding mechanismin which the same means which picks up the sheet from the feed tablefeeds such sheet directly to the impression cylinder without requiringany intermediate conveying means.

Still another object is to provide stack hold down and air blast meansadapted to cooperate with such rapidly operating sheet feedingmechanism.

Other objects of this invention will appear asthe description proceeds.To the accomplishment of the foregoing and related ends, said inventionthen comprises the features hereinafter fully described and particularlypointed out in the claims, the following description and the annexeddrawings setting forth in detail certain illustrative embodiments of theinvention, these being indicative, however, of but a few of the variousways in which the principle of the invention may be employed.

In said annexed drawings:

Fig. 1 is a top plan view of a printing press constructed in accordancewith my invention showing the feed table, sheet feeding and registeringmechanism and the impression cylinder;

Fig. 2 is a front elevational view of such press;

Fig. 3 is a vertical sectional view taken along the line 3-3 on Fig. land showing the suction means of the.

sheet feeding mechanism in position to seize a sheet on the stack;

Fig. 4 is a similar sectional view but showing a position of such sheetfeeding mechanism after it has advanced a sheet to the impressioncylinder;

Fig. 5 is a top plan view of one of the sucker fingers extending from afragmentary portion of the sucker bar; Fig. 6 is a sectional view takenalong the line 6-6 on Fig. 5;

Fig. 7 is a view similar to Fig. 6 but showing the along the line 8-8 onFig. 5; Fig. 9 is a fragmentary sectional view of the sucker barmounting taken along the line 9-9 on Fig. 4;

Fig. 10 is an elevational view of the mounting of the "forward register;

Fig. 11 is a sectional view of such mounting means taken along theline11-11 on Fig. 10;

2,698,175 Patented Dec. 28, 1954 12 is a vertical sectional view similarto Fig. 3 but illustrating a modified form of sucker bar mounting means;

Fig. 13 is a fragmentary view of the sheet feeding mechanism of Fig. 12in the course of elevating a sheet from the stack;

Fig. 14 is a fragmentary view showing the positions of the parts afterrelease of the sheet by the sucker tips;

Fig. 15 is a fragmentary top plan view of the sucker bar mounting meansshown in Figs. 12-14;

Fig. 16 is a fragmentary front elevational view of such mountmg means;

Fig. 17 is a fragmentary top plan view of another modified form of suchmounting means;

Fig. 18 is a vertical sectional view corresponding to a mirror mage ofFig. 3 but illustrating the cylinder press gmpltlaymg feeding mechanismof the type illustrated in Fig. 19 is a vertical sectional view takenalong the line 19-19 on Fig. 18;

Fig. 20 is a sectional view taken along the line 20-20 on Fig. 18;

Fig. 21 is an elevational view of the side registering means showing asheet being engaged thereby; and

Fig. 22 is an end elevational view of the sheet registering means ofFig. 21. Referring now more particularly to said annexed drawlngs andespecially Figs. 1-4 inclusive, one form of press in which I contemplateemploying my new sheet feeding mechanism comprises side frame members 1and 2 reinforced by cross brace 3. Between such frame members ispositioned a feed table 4 of conventional design adapted to support astack of sheets 5 and provided with side gauges 6 and 7. Longitudinalslots 8, 9 and 10 are provided for gauges for the rear edge of suchstack, only one gauge 11 being required for the size of stackillustrated in Figs. 1 and 2. The usual stack elevating means (notshown) will be employed operative to elevate the feed table and stack assheets are withdrawn from the top of such a stack. Y

A back plate 12 is provided against which the forward side of the stackis adapted to rest, such plate having a number of slots 13 in its upperedge through which air from the air blast means may be emitted.

Journaled in the side frame members 1 and 2 is the impression cylinder14 which is adapted to be driven through gear 15. Feed plate 16 extendsbetween such cylinder and the forward edge of the stack. Adjacent theforward edge of the stack such feed plate is flanged downwardly, suchflange 17 being slightly spaced from back plate 12. Fitted in suchintervening space is a freely slidable hold down means comprising ametal sheet, the upper edge of which is bent into a depending flange 18adapted to rest upon the forward edge of the stack. The metal sheetforming such hold down means is provided with openings corresponding toopenings 13 in back plate 12 so that the air blast from longitudinalchamber 19 under feed plate 16 is permitted to reach the forward edge ofthe stack. A second parallel chamber 20 is provided under feed plate 16adapted to direct a blast upwardly through openings 21 for the purposeto be described below.

The sheet feeding mechanism is reciprocated through the oscillationof'rocker arm 22 about its pivotal mount 23. Such rocking or oscillationof arm 22 is accomplished through'the following means. A gear 24 drivenwith impression cylinder 14 meshes with gear 25 to drive a sprocket 26connected by chain drive 27 with sprocket 28. Sprocket 28 drives a largecam 29 which also has a cam track 30 slotted in its outer face.Adjusting arm 31 may be locked by means of lock nuts 32 and 33 indesired position to urge idlerroller 34 against endless chain 27,thereby maintaining the proper degree of tension in the latter. Rockerarm 22 is provided with a cam roller 35 traveling in cam track 30,whereby such rocker arm will be oscillated back and forth as cam 29revolves.

A guide-way 36, having a longitudinal slot 37 therein, is pivotallymounted at 38 in a side bracket 39 in turn pivotally mounted onsideframe 2 at 40. An adjusting screw 41, passing through bracket 39 andbearing on ,feedplate 16, is operative to adjust-ably tilt bracket 39 tothe right. relieved in local areas to permit the advance'of the-suckert1ps,- and the individual segments of which such'roll is #comprisedmaybe moved'along shaft" 74 into anyd'esired about its mounting 40 andthereby to effect a delicate adjustmftt' of' the-location of' pivotalmounting 38' ofguideway Referring now additionally to Fig. 9 of thedrawing, the end *of :tubular sucker ba'r 42 is provided with anoffset-brace arm"43, both: such a'rms having ball bearing journaledrollers 44 and 45 respectively adapted to''- travel insl'ot 37 ofguide-way 36. Also pivotally connected to the endof sucker bar'42 is' 'a-1ink'46 connected to he upper end of rocker arm 22. The other 'erid ofguideiway -36- fr'om its pivotal F mount 38 carries I a I cam- 'roller47' adapted to 'run on the periphery of canrZQ. The coil spring '48serves-to maintain s'uch'roller in close engagement with such cam. -As'shown in' Figs. 1 and :2,the oth'er end of sucker bar 42 is supportedand oscil lated by means which are the exact mirror image of the meansabove des'cribed'and illustrated in Figs. 3 and 4; shaft 49 driven bygear 25 servingto synchronously drive the =sprocket corresponding'to'sprocket 26"on-the other side -'of'-the press. Like' numerals will,therefore,- be employed to designatelike parts of such mechanism.

Now referring to Figs. 1 and -8 of the drawing; tubular sucker bar 42,which-'is olosed ateachend, is provided with a flexible hose connection50=leading to a suction "pump cn'ot shown). such' sucker bar-carries aplurality of fingers, the construction of whichis best illustrated inFigs. 5+8. Each -finger comprises a tube 51 extending laterally forwardfrom "within-such s'ucker bar in 1 which is sleeved a 'protr-uding tube52 closed at each end. Tubular extension 51 -is slotted-near its ex--tremity -and provided' with-wings"53 and 54, whereby tube -52 -'may betightly clamped by adjustment of knurled screw 55. A sucker tip 56,preferably of 'rubber, is -inounted at rightangles to theend of tubeSZ-a'nd cOm- *municates -with the *interior thereof. An opening 57 1sprovided in the lowerwallof tubular extension 5l' within sucker bar' 42and a similar opening "5815 provided in thewall of tube 52 adapted'tocoincide-with such firstnamed opening When'sucker tip 56 is turneddownwardly. as s hown in'Fig. 6, andnot to socoincidewhen suchsuckertip'is turned upwardly, as shown-in Fig. 7. It will, therefore, beseenthat a sle'eve 'valve has-'been provided whereby thesucker tip is incommunication with the interior of sucker bar 42 when such -su'cker tip13 tul'ned downwardly injposition to-contact the 'topmo st "-sheet' ofthe stack but which wilhplacesuch sucker tip out of communication withthe-interior of 'the 'su'ckerbar when such sucker tipis 'turnedupwardly'as shown-an Fig. 7. In operation,-as 'shown'in Fig. 1, onlythose sucker-tips adapted to contact the sizegof sheetbelng fed willbeturned downwardly with the 'others'turned up to close offcommunication with the-suckerb'ar as WeIl 'as 'toavoidpossibility ofinterference with theside register described I below.

The forward register is in the form of a long-comb'59 having dependingfingers 60. As best-'shown in Figs. 1, '3, and 11, 'such register isclamped to rocker-shaft 61 journaledinside frames 1 and 2bymeans ofclamps 62 and 63. 'As shown -in Fig. l1,' each of these clamps.

- comprisesa 'split'bushing adapted to'be drawn into tight engagernentwith sha'ft'61 by means of scr'ewl 64. The register is-attached theretoby bolt 65 and bac'ked by a coil spring 66, whereby damage to themechanism will be prevented should such register accidentally contactotherparts of the me'chanisnwin operation. A5 fbest shown in Figs. 1 and3, the end-of:'shaft 6l protrtlding "through side frame member lcarries*aishortt'leverlarm 1 and cam roller 67 1 adapted: 'to" ride theperiphery of cam #68 driven with the impressionz-cylinder 14.A=?torsion. spring 69'acts"on SUch deVer -arm to hold -rdlle1f-:67Hinclose contact-with-the periphery of cam-'68. vSuch cam 'isshaped to rockshaft 61 back and' forth to 'swing1 for- =ward f register 59- in and outi of operative position.

A'zpulley 70 drivenwith"cam 68 "is" adaptedto be'connected' to smallerpulley 71' by means of a V-belt" (-not *shown). Pulley 7l -isadapteditodrive sp'ur gear' 'lz,

"which in turn drives gear' 73 and shaft" 74. Mounted *on "shaft74"forro'ta'tion therewith is a'ro1l 75-bearing'a ":spiral r1b'76-"aboutits periphery,}pr'eferably ofrubber. ."As shown in the drawing;when"'roll75 is rotated in the 'directionillustrated in Fig. 3, suchspiraljwill 'rnove Roll 75 is interrupted or circumferentially position.As best shown in Figs. 21 and 22, the side register comprises a small'vertical flange '77 carried on a laterally adjustable plate member 78which may be locked in desired position "by means of nut 79 threaded onstud 80.

The operation of my.new sheet feeding mechanism is as follows. Slot 37is so shaped that as rocker arm 22 swings rearwardly, the sucker bar 42and the sucker tips carried thereby will be rocked in counter-clockwisel0 direction, asviewed in Fig. 3. At the same time roller 47 encountersdepression 81 in the periphery of cam 29 thereby tilting guide-way 36abruptly to lower the sucker tips into engagement with the forwardportion-of the topmost sheet of the stack as illustrated in Fig. 3. Atthis point, the air blast from chamber 19 comes on tending to fluff upand separate the uppermost sheets of the stack. Thesuctionthen comes onin such sucker bar and the sucker tips seize the sheet. Rocker arm 22cont'inues its rearward movement for a short distance sufficient towiithdrawlheforward edge of the sheet' from beneath hold down 18.Simultaneouslyroller 47-encounters theabruptxshoulder on cam '29succeeding depression sl :and. abruptly elevates/guide-way36 and thesucker bar and "sheet carried thereby. .As rocker arm l22now swingsforward,' the.upward turn of slot-'37 causes the-sucker tips.andltherefore the: leading edge of the sheet to-"beslightlytupwardly'inclinedcausing such edge to :planethrough the air"withoutdrooping. The degree of isuch inclination may be regulated by adjustingscrew "41 'even 'to a point oflafl'ording no inclination whatsoever ifdesired. As the sucker'tipsapproach the forward limit 'of their movementbetween"the'segments of'roll 75 with the forward edgeof the sheetextending between "the --lower- 'surface 'of-Y'such rolland the surfaceof'feed plate 30 16;the suction is'turned'off and the sheet released."At

-thispoint,ithe air iblast from chamber 20 through open- -ings21icomeson causing the sheet tobe pressed upwardly 'against the spiral ribs'ofrevolving roll75. Si-

multaneously with the foregoing; roller 67 riding on cam f68 has'rockedshaft fl' to swing" forward register fingers 60 down into'gaugingposition. The rotation of roll' 75 'bringsthe forward edge of the sheetinto gauging engagement 'with such fingers and at the same time themovement of the spiral ribs 76 to theri'ght carries the 40fioatingi'sheet into 'gauging engagement with side reg- Tister 77.Because-"of the fact that-the sucker tips have already carried the sheetso close to the'impression cylinder,1there is: little loss"of registerbetween the stack and the above described registering means so' thatonly slight 5oad ustment of the-sheet need beetfe'cted if thestack hasbeenprop'erly positioned upon the feed table. "Register ifingers-60 now'swing back again'and sheet grippers 82 of theimpression cylinder seizethe forward edge of the sheet. Rocker-arm 22 is'now swinging'rearwardlyagain and' 'the operation=is repeated. Ithas been found that sheetfeeding mechanism of the typedescribed is capable of exceedingly rapidoperation and, indeed, itis believed that for the first time sheetfeeding means has beenprovidedcapable' of feeding individualsheets froma stack at'a rate comparable to that at which a press of this type maybe effectivcly'run. Thus, the speed of operation of the sheet feedingmechanism is no-longer "the limiting factor-in'the operation of thepress as has been '-'the casein the' past. "The same sheet may be runthrough the'press as many as seven-times without apparentloss "ofregister.

Figs. 12-16 illustrate a modified form of my new sh'e'et feedingmechanism in which 'the' guide-way for the suckerbariniits'reciporcation isnot adaptedto be tilted but is fixedlyattached ateach end to side frame member 2. As the driving'rneans' andregistering means are the s'ame" as in the first embodiment of myinvention above described, like pa'rts will be designated by likenumerals.

Means for controlling the rotative movement of the 'lfi sucker bar aboutits axis is provided, however, on but one "side of =thepress as suchmeans is sufficiently positivein its effect not to require duplication.

A straighh'guide-way 83 in 'the form of a tubular bracket is rigidlyattached to'- sideframe member 2 and s'upportsa slide'84' sleevedthereon in which one end of sucker bar'42 is inounted for pivotalmovement about -its-a'xis. "Such slide' 84'is also'pivotally connectedby means of link 85 to the upper end of rockerarm 22 so -that as sucharm- 22 is oscillated by rotation of cam 85 86, slide 84 and Sucker-bar42will be reciprocated along guide-way 83. Mounted on the end of suckerbar 42 for rotation therewith is a bracket member having arms 87 and 88extending therefrom approximately at right angles to each other. Arm 87is adapted to contact the under surface of an eccentric 89 mounted onslide 84 thereby limiting clockwise rotation of sucker bar 42 as viewedin Fig. 12. A delicate adjustment of the degree of such clockwiserotation is obtainable by turning such eccentric.

The other, upwardly extending, arm 88 carries a cam roller 90 at its endadapted to engage the under surface of arm 91 pivotally mounted at 92about guide-way 83 on side frame member 2. Integral with such finger 91is another inner finger 93 carrying an upwardly extending bolt 94 whichpasses freely through a boss 95 on side frame member 2. A spring 96between boss 95 and arm 93 tends to urge such arm downwardly to theextent permitted by nut 97. Upward pressure on such arm will, of course,result in compression of spring 96 and upward movement of bolt 94through boss 95. The lower surface of arm 91 contacting roller 90provides a cam track having a shoulder 98 succeeded by a depression 99.A spring 100 serves to maintain roller 90 in close engagement with theunder surface of arm 91.

In operation, as rocker arm 22 swings to the right, as viewed in Fig.12, roller 90 encounters shoulder 98 causing sucker bar 42 to be rotatedin a counter-clockwise direction and bringing the sucker tips intocontact with the top of the stack. Just prior to such contact, the airblast from longitudinal chamber 19 has been turned on to fluff up theforward portion of the stack. As rocker arm 22 swings still further tothe right, the sucker tips, now grasping the sheet, are caused towithdraw the same from beneath the lip of hold down 18. During suchmovement roller 90 passes shoulder 98 and depression 99. Thereupon,sucker bar 42 is rotated abruptly in a clockwise direction and thesucker tips elevated with a snap action to raise the forward portion ofthe sheet as shown in Fig. 13. Rocker arm 22 is now swung to the left ascam 86 continues to turn, moving slide 84 to the left along guide-way83. Stop 89 limits the rotation of sucker bar 42 in a clockwisedirection so cam roller 90 is effective to push up arm 91 as it passesprominence 98. After the sucker tips have advanced between the segmentsof roll 75, the sheet is released for registering as shown in Fig. 14.The sheet feeding mechanism then repeats the cycle, the sheet beingregistered and seized by impression cylinder grippers 82 in the samemanner as previously explained.

A modified embodiment of the mechanism of my invention is illustrated inFigs. 17-20 where guide-way 101 is mounted on studs 102 and 103 carriedby bracket plates 104 respectively welded to side frame members 1 and 2.Sucker bar 42, here of rectangular cross section as shown in Fig. 18, ispivotally connected at each end by means of pins 105 to slides 106adapted to be reciprocated along such guide-ways 101. Arms 107 extendingforwardly from such sucker bar are connected to brackets 108 on suchslides by means of tension springs 109. The means for reciprocatingslides 106 along guideways 101 are substantially identical with thatpreviously illustrated and described and the parts are accordinglyidentified by like numerals. A slightly different form of device formaintaining chain 27 in tight engagement with the sprockets is, however,shown comprising an idler wheel 110 carried at the end of threaded rod111 adapted to be locked in adjusted position relative to lower framemember 114 by means of nuts 112 and 113.

As best shown in Figs. 18 and 19, the left-hand end of sucker bar 42carries an upwardly extending lever arm 115 bearing a cam roller 116 atits upper end, such lever arm corresponding generally to lever arm 88 ofthe Fig. 12 embodiment. Pivotally mounted on boss 117 is a slotted arm118 carrying on its lower surface a cam track member 119 adjustablelongitudinally along such slot and adapted to be retained in desiredposition by means of screw 120. The action of springs 109 serves to holdroller 116 in close contact with such cam track 119. Limiting the degreeto which such springs are effective to rotate sucker bar 42 in acounter-clockwise direction, as viewed in Fig. 18, is an adjustablescrew 124 fastened in arm 118 extends upwardly through an aperture inbracket 123 and carries an adjusting nut 125 threaded thereon. Betweensuch nut and such bracket about such pin is a compression spring 126. Itwill, therefore, be seen that by turning such nut to compress suchspring, the pressure urging arm 118 and therefore cam track 119-downwardly into engagement with roller 116 may be regulated as desired,a cotter pin 127 preventing pin 124 from being drawn through theaperture in bracket 123. t

The operation of this last-described embodiment of my invention issubstantially that of the embodiment shown in Figs. 12-16. However,after seating cam track 119 in the proper position, the angle at whichthe advancing sucker tips will carry the sheet may be regulated byadjusting screw 121 so that the forward edge of very thin sheets ofpaper may be rather sharply upwardly inclined, whereas heavier andstiffer sheets will be given a relatively small degree of inclination,the rectangular cross section of sucker bar 42 affording a sufficientdegree of clearance. In Figs. 17 and 18, the ribbed register roll 75 isshown driven directly by means of-a belt 128 and a pulley 129 instead ofthrough the pulley and gear train as shown in Fig. 1. Its operation is,however, identical.

It will be seen from the foregoing that I have provided new sheetfeeding mechanism which is adapted for very rapid operation and may bereadily adjusted to accommodate either heavy or light sheets. Since aslittle as 2% inches may intervene between the forward edge of the stackand the point where the grippers on the impression cylinder seize theforward edge of the sheet, it is obvious that the press may be of -verycompact construction, a matter of some importance to small jobbers andthe like. Because of the small distance between the stack and theimpression cylinder, sheets may be fed as rapidly as the press mayotherwise be run without the complexity of lapped feeding usuallyrequired when operating presses at high speeds. Despite such high speedoperation, exceedingly accurate register is obtained due partly to theshort distance and positive control over the sheet being advanced andpartly to my novel register means which quickly performs any finalslight adjustment in the position of the sheet required before suchsheet is snatched by the gripper means on the impression cylinder.

This application is a division of my co-pending application Serial No.696,992, filed September 14,1946, now abandoned.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims or the equivalent of suchbe employed.

I therefore particularly point out and distinctly claim as my invention:

1. In sheet feeding mechanism, suction means operative to seize andadvance the topmost sheet of a stack, a guide-way for said suction meansas it thus advances, means operative to tilt 'said guide-way during suchadvance, and means operative to tilt said suction means relative to saidguide-way during such advance.

2. In sheet feeding mechanism, suction means operative to seize andadvance the topmost sheet of a stack, a guide-way for said suction meansas it thus advances, means operative to tilt said guide-way to elevatesaid suction means during such advance, and means operative to tilt saidsuction means relative to said guide-way during such advance.

3. In sheet feeding mechanism, suction means operative to seize thetopmost sheet of a stack adjacent its forward edge and advance the same,a guide-way for said suction means as it thus advances, means operativetoelevate said guide-way to elevate said suction means during suchadvance, and means operative to tilt said suction means relative to saidguide-way to upwardly incline the forward edge of such sheet during suchadvance.

4. In sheet feeding mechanism, suction means operative to seize thetopmost sheet of a stack adjacent its forward edge and advance the same,a guide'way for said suction means as it thus advances pivotally mountedfor oscillation in a vertical plane, cam means operative to tilt saidguide-way about such pivotal mounting to elevate said suction meansduring such advance, and cam means operative to tilt said suction meansrelative 57 ,to said guideway to upwardly ,inclinethe forward edge,of-such sheetduring such advance.

,5. In sheet feeding mechanism, suction means operativeto. seize andadvance the topmost sheet of a stack comprising a horizontal pivotallymounted sucker bar, ztubular arms extending therefrom over such stack,sucker tips-rigidly fixed to thefree ends of said arms adapted .toengagethe upper surface of such stack, and a lever ,arm on said pivotallymounted sucker bar; a guide-way inclined relative to such stack alongwhich said sucker bar; is adapted to be laterally reciprocated; andmeans ,operative on said lever arm to rock said sucker bar abruptly-toelevate said sucker tips immediately after seizing such-sheet to elevatesuch sheet from such stack.

6.-In sheet, feeding mechanism, suction means opera- :tive to seize andadvance the topmost sheet of a stack comprising a horizontal pivotallymounted sucker bar, tubjular arms extending therefrom over such stack,sucker tips rigidly fixed to the free ends of said arms adapted toengage the upper surface of such stack, and a lever arm onsaid pivotallymounted sucker bar; a guide-way along 'which said sucker bar, is adaptedto be laterally reciprocated; means operative on said lever arm to rocksaid sucker-bar abruptly to elevatesaid sucker tips immediately afterseizing such sheet, and a stop adapted tolimit the degree of elevationof said sucker tips.

7.--In sheet'feeding mechanism, suction means opera- --tive to seize andadvance the topmost sheet of a stack comprising a horizontal pivotallymounted sucker bar, tubular arms extending therefrom over such stack,sucker tips rigidly fixed to the free ends of said arms adapted tovengage the upper surface of such stack, and a lever .:arm on saidpivotally mounted sucker bar; a guide-way .-along which said sucker baris adapted to be laterally -reciprocated; a roller on the end of saidlever arm; a v

cam track resiliently engaging said roller; resilient means urging saidroller into engagement with said track a shoulder .on said track adaptedto rock said lever arm and sucker baras said sucker bar is reciprocatedin one direction, whereby said sucker tips will be depressed intoengagement with the top of such stack; a recess in said track beyondsaid shoulder adapted to permit said lever arm and sucker bar to rockabruptly to elevate =said sucker tips upon further reciprocation in thesame direction; and a stop limiting the degree of elevation of saidsucker tips upon reciprocation past said shoulder in the oppositedirection.

8. In sheet feeding mechanism, means operative to seize and advance thetopmost sheet of a stack comprising apivotally mounted carriage andsuction means rigid- 1y fixed to and disposed forwardly of saidcarriage; a guideway along which said carriage is adapted to bereciprocated; means for rocking said carriage comprising a lever armfixed thereto, a cam roller on said lever arm, a resiliently backed camtrack adapted to engage said 'roller, resisient means urging said rollerinto engagement with said track, a shoulder on said cam track adapt- .edto rock said lever to depress said suction means as said carriage isreciprocated in one direction, and a .stop adapted to limit the degreeof elevation of said suction means upon reciprocation of said carriagein the opposite direction.

9.-Insheetfeeding mechanism, means operative to seize and advance thetop-most sheet of a stack comprising a pivotally mounted carriage andsuction means rigidly fixed to and disposed forwardly of said carriage,a guide-way along which said carriage is adapted to be reciprocated, alever arm fixed to said carriage, means operative to rock said lever armto depress said suction means into engagement with the top-most sheet ofsuch stack, andmeans operative to rock said lever arm abruptly toelevate said suction means immediately after seizing such sheet.

10. In'sheet feeding mechanism, means operative to -seize and advancethe top-most sheet of a stack com-.

prising a horizontal pivotally mounted sucker bar, tu-

bular arms extending therefrom over such stack, sucker -tips rigidlyfixed to the ends of said arms adapted to engage the upper surface ofsuch stack, and a lever zarm on said pivotally mounted sucker bar; aguide-way along which said sucker bar is adapted to be reciprocated; ;,a-cam-roller on the end of said lever arm, a cam track resilientlyengaging said roller, resilient means urging i said roller-intoengagement with said cam track, a shoulder onpsaid cam track adapted torock said leverv arm vandspckerbar, as'the latter is reciprocated inonedirection and thereby depress-said suckertips intoengagementtwith thetop of such.stack, a recess insaid camtr'ack beyond said shoulderadapted to permit said lever; arm and sucker bar to rockabruptly toelevate said. sucker tips upon further reciprocation of said sucker .bar-m the .same direction; astop limiting the degree of.elevati0n press orthe like which comprises subjecting the forward .edge of a stackof'sheets to a blast of air and themedvancing the top-most sheet,thesteps of yieldably-holding down the forward edge portion of suchstackof sheets, moving the top-most sheet rearwardly to free the forwardedge thereof, then abruptly elevating .the portion of such sheetadjacent the forward edgecthereof and advancing the same.

12. In the method of feeding sheets to a printingpress or the like whichcomprises subjecting the forwardedge of a stack of sheets tea-blast ofair and then.advancing the top-most sheet, the steps of yieldablyholding down the forward edge portion of such stack of sheets, movingthe top-most sheet rearwardly to free the forward edge thereof, thenabruptly elevating the portion of such sheet adjacent the forward edgethereof and advancing the same, and upwardly inclining the forwardportion of such advancing sheet.

13. In sheet feedingmechanism, means operative to seize and advance thetop-most sheet of a stack comprismounted to rock said sucker tipsintoand outof stackvengaging position, resilientmeans urging saidsuckertips upwardly, and cam means adaptedto rock said carriage todepress said sucker tips into stack-engaging position against the actionof said resilient means during v rearward movement of said carriage andthen to release said carriage for abrupt upward movement of saidsuckergtips under the. infiuencelof said resilient means prior to-thenext forward movement of said carriage.

14. In sheetfeeding mechanism, means operative to seize and advancethetop-most sheet of.a stack comprising a carriage and suction meansrigidly fixed toand disposed forwardly of. said carriage, aguide-wayalong which said carriage is adapted to be reciprocated to movesaid suction means from a position abovesuch stack to a positionforwardly thereof, said carriage being pivotally mounted to rock saidsuction means .into and out of stack-engaging position, means adapted.to rock said carriage to depress said suction means into stack-engagingposition during rearward movement of References Cited in the file ofthis patent UNITED STATES PATENTS Number Name Date 488,212 ,MastersonDec. 20,1892 824,920 Erickson July 3, 1906 1,133,807 Lagerman et al Mar.30, 1915 1,207,365 Broadmeyer Dec. 5, 1916 1,435,205 'Brigham Nov. 22,1922 1,488,673 Henderson Apr. 1,1924 1,625,578 Tremper Apr. 19, 19271,834,382 Cheshire Dec. 1, 1931 1,867,038 Upham July 12, 1932 1,966,320Tate July 10, 1934 2,097,587 Dearing Nov. 2, 1937 2,132,283 -Allen Oct.v4, .1938

2,169,400 Strongberg et a1 Aug. 15, 1939 2,182,435 Huck Dec. 5,' 19392,207,492 Speiss July-,9; 19,40

:(Otlwr references onlfollowing ,page) Number Name Date Seybold Sept.10, 1940 Christensen Aug. 26, 1941 Sundstrand May 12, 1942 Robinson Feb.16, 1943 Lake et a1 June 6, 1944 Bernard et a1 Apr. 24, 1945 NumberNumber 10 Name Date Eckman Aug. 14, 1945 Perry June 18, 1946 WilliamsJan. 13, 1948 FOREIGN PATENTS Country Date Germany July 10, 1930

